1. Field of the Invention
The present invention relates to an apparatus which is formed by brazing plural metal members, and a brazing method for manufacturing the apparatus. The present invention is suitable for a case where a brazing material can be clad or applied on only one surface of a metal member, or a case where a brazing material can be clad or applied on both surfaces of the metal member while a core plate of the metal member is made thicker by thinning the brazing material on one surface of the metal member.
2. Description of Related Art
As a method for brazing two metal members, contacting surfaces of the two metal members are generally clad or applied with a brazing material. However, in a case where only one surface of the metal member can be clad or applied with the brazing material from characteristics of a product, the method may be difficult to form the product by brazing plural metal members.
For example, as shown in FIGS. 3A-3C, a brazing material R is clad on an inner surface 11b of a plate 11, and the inner surface 11b of the plate 11 is brazed to an another plate (not shown) using the brazing material R so that a tube 10 is formed. When a connection block 12 for connecting a pipe (not shown) to the tube 10 is brazed to the plate 11, a brazing material is clad on a contacting surface of the block 12, contacting the plate 11, or is clad on a contacting surface 11a of the plate 11. Because the connection block 12 is necessary to form a female screw portion 12a through a mechanical step (i.e., screw forming step), it is impossible to cold the brazing material on the contacting surface of the block 12. Therefore, a sheet-like brazing material is clad on the contacting surface 11a of the plate 11 as shown in FIG. 3A, a ring like brazing material is provided at a corner between the connection block 12 and the plate 11 as shown in FIG. 3B, or a paste like brazing material is applied on the corner between the connection block 12 and the plate 11 as shown in FIG. 3C.
Thus, in addition to the brazing material for forming the tube 10, an another brazing material for brazing the connection block 12 to the plate 11 is also necessary. Therefore, brazing steps are increased, and an apparatus formed by brazing plural metal members, such as a heat exchanger, is produced in high cost.